103 research outputs found

    Effect of a congested match schedule on immune-endocrine responses, technical performance, and session-RPE in elite youth soccer players

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    This study investigated the effects of a congested match schedule (7 matches played in 7 days) on steroid hormone concentrations, mucosal immunity, session rating of perceived exertion (S-RPE) and technical performance in 16 elite youth soccer players (14.8 ± 0.4 yr; 170.6 ± 9.4 cm; 64.9 ± 7 kg). No change was observed for salivary cortisol concentration across multiple matches (p=0.33; Effect size [ES]=0.13-0.48). In contrast, there was a decrease in salivary testosterone and IgA concentrations (SIgA) from the 1st compared to the last time-point (p=0.01 and 0.001, ES=0.42 and 0.67, respectively). The SIgA concentration varied across time points (p 0.05). A higher number of tackles and interceptions were observed during the 4th match vs. 1st and 7th matches (p<0.001; ES=2.25 and 1.90, respectively). The present data demonstrate that accumulated fatigue related to participation in a congested match schedule might induce a decrease in testosterone concentration in youth players’ and negatively affect their mucosal immunity and capacity to perform certain technical actions

    Validade e reprodutibilidade de receptores para o GPS em relação à distância percorrida Validez y reproducibilidad de receptores GPS en relación de la distancia recorrida

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    ResumenObjetivoEl presente estudio evaluó la validez y reproducibilidad de dos modelos de receptores para el Global Positioning System (GPS). La validez fue evaluada comparando la distancia registrada por los receptores con la distancia conocida de estos trayectos.MétodoSeis jóvenes tenistas (177,6±6,2cm; 76,6±3,2kg) recorrieron tres trayectos: 1) 100m en la pista de atletismo (número de “disparos” = 120); 2) 400m en la pista de atletismo (número de “disparos” = 60) y 3) 100m con cambios de dirección (número de “disparos” = 120), utilizando los equipos Garmin© Forerunner 405 y Polar© RS800.ResultadosEn los trayectos sin cambios de dirección (100 y 400m), a través de la ANOVA two way (distancia y velocidad) no se detectaron diferencias entre la distancia conocida y las distancias registradas por los receptores analizados (p>0,05). En el trayecto de 100m con cambios de dirección, se observaron diferencias entre la distancia conocida y las registradas tanto por el Polar© RS800 como por el Garmin© Forerunner 405 (p<0,05). También se verificó la diferencia en las distancias registradas por el Polar® RS800 y por el Garmin© Forerunner 405 para el trayecto realizado con cambios de dirección (p<0,05).ConclusiónA través de los datos, se puede afirmar que los receptores para GPS evaluados presentaron un nivel aceptable de precisión para distancias recorridas sin cambios de dirección, sin embargo, la precisión de estos equipos en trayectos con cambios de dirección fue limitada.AbstractObjectiveThe present study evaluated the reproducibility and validity of two models of receivers for the Global Positioning System (GPS). Validity was assessed by comparing the distance recorded by the GPS receivers with the known distance.MethodSix young players (177.6±6.2cm; 76.6±3.2kg) performed three routes with different characteristics: 1) 100m in the athletics track (number of “sprints” = 120); 2) 400m in the athletics track (number of “sprints” = 60) and 3) 100m with changes of direction (number of “sprints” = 120), using equipment Garmin© Forerunner 405 and Polar© RS800.ResultsRegarding linear routes (100 and 400m), no differences were detected using ANOVA two-way (distance and speed) between the known distance and distance recorded by GPS receivers analyzed (p>0.05). Regarding non-linear route of, significant differences were observed between the known distance and recorded distance by the GPS receivers (p<0.05). There was also a significant difference between the distance recorded by Polar© RS800 and Garmin© Forerunner 405 for the non-linear route (p<0.05). Analysis of the limits of agreement reinforces the limitation of equipment in relation to accuracy for the non-linear route.ConclusionThese data suggest that the GPS receivers evaluated showed acceptable level of accuracy for linear routes, however, the accuracy of such devices on non-linear routes was limited

    Quasi Free 238U (e,e'f)-Cross Section in Macroscopic-Microscopic Approach

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    We present the result of a theoretical study of inclusive quasi free electrofission of 238^{238}U. The off-shell cross sections for the quasi free reaction stage have been calculated within the Plane Wave Impulse Approximation (PWIA), using a Macroscopic -Microscopic description of the proton and neutron single particle momentum distributions. Electron wave function distortion corrections were included using the effective momentum approximation, and the Final State Interaction (FSI) effects were calculated using an optical potential. The fissility for the proton single hole excited states of the residual nucleus 237^{237}Pa was calculated both without and with contributions of the pre-equilibrium emission of the particles. The fissility for 237,238U^{237,238}U residual nuclei was calculated within the compound nucleus model. The (e,ef)(e,e^{\prime}f)-cross sections thus obtained were compared with available experimental data.Comment: 26 pages, 7 figure

    Changes in evapotranspiration, transpiration and evaporation across natural and managed landscapes in the Amazon, Cerrado and Pantanal biomes

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    Land-use and land-cover change (LULCC) can dramatically affect the magnitude, seasonality and main drivers of evaporation (E) and transpiration (T), together as evapotranspiration (ET), with effects on overall ecosystem function, as well as both the hydrological cycle and climate system at multiple scales. Our understanding of tropical ecosystem responses to LULCC and global change processes is still limited, mainly due to a lack of ground-based observations that cover a variety of ecosystems, land-uses and land-covers. In this study, we used a network of nine eddy covariance flux towers installed in natural (forest, savanna, wetland) and managed systems (rainfed and irrigated cropland, pastureland) to explore how LULCC affects ET and its components in the Amazon, Cerrado and Pantanal biomes. At each site, tower-based ET measurements were partitioned into T and E to investigate how these fluxes varied between different land-uses and seasons. We found that ET, T and E decreased significantly during the dry season, except in Amazon forest ecosystems where T rates were maintained throughout the year. In contrast to Amazon forests, Cerrado and Pantanal ecosystems showed stronger stomatal control during the dry season. Cropland and pasture sites had lower ET and T compared to native vegetation in all biomes, but E was greater in Pantanal pasture when compared to Pantanal forest. The T fraction of ET was correlated with LAI and EVI, but relationships were weaker in Amazon forests. Our results highlight the importance of understanding the effects of LULCC on water fluxes in tropical ecosystems, and the implications for climate change mitigation policies and land management

    Impact of adding different concentrations of IGF-I and insulin to the semen extender on bull sperm quality post-cryopreservation

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    ABSTRACT This study aimed to evaluate the addition of different concentrations of IGF-I and insulin to egg yolk-based extender to improve bovine semen cryopreservation. Two experiments were developed to evaluate the effects of the additives in two commercial extenders, Botubov® (Experiment 1) and Triladyl® (Experiment 2), both with the same design. Three ejaculates from four bulls (n = 12) were used. Each ejaculate was divided into seven equal fractions for dilution (60x106 spermatozoa/mL) in the following treatments: CON: extender only; IGF100: IGF-I 100ng/mL; IGF200: IGF-I 200ng/mL; INS150: insulin 150µUI/mL; INS200: insulin 200µUI/mL; ASS1: IGF-I 100ng/mL + insulin 150µUI/mL; ASS2: IGF-I 200ng/mL + insulin 200µUI/mL. Semen was cryopreserved by an automated system. Post-thawed sperm were evaluated regarding motility by CASA (Computer-assisted sperm analysis), and membranes by fluorescent probes (H342, PI, FITC-PSA and JC-1). For Botubov® extender, INS150 was more efficient in preserving total and progressive motility, VCL, BCF, plasma and mitochondrial membranes. A similar response was seen when insulin was added to the Triladyl® extender, INS150 was more efficient in preserving sperm motility, plasma membrane integrity and mitochondrial potential. Thus, the addition of insulin 150µUI/mL, regardless of the composition of the extender, contributes to better preserving bovine sperm from the cryopreservation effects

    CARACTERIZAÇÃO DO MODELO INFLAMATÓRIO DE CISTITE INDUZIDA POR CICLOFOSFAMIDA EM CAMUNDONGOS SWISS

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    A Cistite Hemorrágica é um problema de saúde importante no mundo causado pelo uso da oxazoforinas. Apesar dos tratamentos disponíveis, há uma incidência de 2 até 40% em pacientes tratados com Ciclofosfamida (CYP). O objetivo deste trabalho foi caracterizar um modelo experimental de cistite induzida por CYP em camundongos Swiss. Para isto, camundongos fêmeas foram distribuídos em 5 grupos com 7 animais, onde 4 grupos sofreram eutanásia após 0,5, 6, 12 e 24h da aplicação de 150mg/kg de CYP via intraperitoneal. O grupo controle recebeu salina tamponada pela mesma via. Foram avaliados o peso da bexiga e seu aspecto histopatológico, o hemograma, e a contagem celular de medula óssea e linfonodo ilíaco. Os resultados demonstraram que houve aumento significativo do peso da bexiga nos tempos de 6 e 12h. Houve aumento na infamação aguda nestes dois tempos. Após 24 horas houve diminuição da resposta inflamatória aguda e início da fibrose. O número de leucócitos foi menor em todos os tempos em relação ao controle. Da mesma forma, o número de células da medula óssea foi menor nos tempos de 6, 12 e 24h. Por outro lado, o número de células do linfonodo aumentou após 12 horas. Concluímos que houve aumento progressivo da inflamação até as 12h  e que após 24h já há um processo de resolução do quadro inflamatório. Sendo assim, sugerimos a utilização do tempo de 12h como padrão experimental por ser o de maior disponibilidade de parâmetros elevados para avaliação da inflamação.Descritores: Cistite. Ciclofosfamida. Camundongo. Modelo experimental.AbstractCharacterization of cyclophosphamide-induced cystitis inflammatory model in Swiss mice. The Hemorragic Cystitis (HC) is an important health problem over the world caused by oxazoforines. Despite the available treatments, still have an incidence of 2 to 40% of HC in patients following treatment with Cyclophosphamide (CYP). The aim of this work was characterize a model of CYP-induced cystitis  in Swiss mice. Female mice were divided  in 5 groups with 7 animals each, 4 groups were killed 0.5, 6, 12 and 24h after an injection of CYP (150mg/kg). The control group received phosphate buffered saline at the same way. In each time the bladders were collected, weighted and prepared to histopathology analyses. The complete blood count was evaluated. The cell number from lymph nodes and bone marrow was quantified. The results showed that bladder weight was increased at 6thand 12th hour pos cystitis induction. There was acute inflammation increased after 6 and 12h. After 24h there was an initial fibrosis. The leucocytes count was decreased in all times. The cells number was decreased at 6th,12th, and 24th hours in bone marrow and it was increased at 12th in lymph nodes. We concluded that there is an increase in inflammatory parameters until the 12th hour pos CYP injection which are decreased at 24th hour. We suggest using the time of 12h as the standard experimental time because of the biggest availability parameters for evaluating.Descriptors: Cyclophosphamide. Cystitis. Mice. Experimental model
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